Code Manual for CONTAIN 2.0 - Federation of American Scientists

= hi,, (for enthalpy tables, k(n)
= liquid water or steam)
It should be noted that the repository pressure Pi used in this equation is a nominal pressure because
the actual source pressure is not known. The repository pressure used for the purposes of energy
accounting is taken for simplicity to be the gas pressure at the gas-center elevation, for all
repositories in a cell. Contrary to what one might expect, this nominal pressure is not adjusted for
the variation in pressure from gas and liquid heads within a cell, since this adjustment would have
a small effect. This choice for the nominal pressure, coupled with the effect of the work done by the
atmosphere on the pool in the pool energy, leads to substantial cancellations of the pressure terms
in the pool state calculations. (The cancellations are related to the fact that the pool state should be
affected by the pressure terms only with respect to viscous losses and the volume by which the pool
is expanded or compressed. Because the pool is treated as incompressible, the effects of the pressure
terms on the pool state should reflect only viscous losses, which vanish in the limit that the source
pressure is equal to the cell pressure.)
Enthalpies for nonaerosol materials from external repositories, such as the gas influxes horn the
CORCON model, are defined on the basis of temperature and pressure matching across the interface:
h~,i,~= h~(~)(Ti,~,Pi,n,~(~)) (for nonaerosol materials from (A-7)
external repositories)
where Ti,~here is the matching temperature and Pi,~,~(n) is the matching pressure.
For all aerosol external fluxes, hi,, is nominally defined at the temperature and pressure of the
repository intowhich the aerosols are introduced. That is,
(for aerosols) (A-8)
where Ti is the repository temperature and Pi is the repository pressure as defined above.
The chemical reaction and fission product decay energy E,j is the sum of the integrated rate at which
heats of reaction are generated from chemical reactions and integrated decay heating rates.
Er,i = f( ‘ qchemi + qm,i)dt’
‘o’
(A-9)
where q,~~~jis the rate of generation of heats of reaction, referenced to 273.15 K, in repository i; and
~,i is the fission product decay heating rate in repository i.
Chemical reaction heats include those from hydrogen bums (including deflagrations, difision
flames, and bulk recombination), debris droplet chemistry, and concrete outgassing. Note that in the
last case only the heats of reaction for release of bound water and C02 are included. Evaporable
water, even with a user-specified heat of evaporation, is treated as usual through an appropriate offset
R O A8 6/30/97